Boat hull construction and propulsion



May 2, 1944. w. s. BRIAN ET AL 2,348,106

BOAT HULL CONSTRUCTION AND PROPULSION 2 Sheets-Sheet I jwuc-Mo'm. W .5. Brian 'F.' JEink v Filed April- 12, 1943 y 2, 1 w. s. BRIAN ET AL 2,348,106

BOAT HULL CONSTRUCTION AND PROPULSION FiI Led April 12, 1945 2 Sheets-Sheet 2 grwvwtou.

Brian J J Eir'k Patented May 2, 1944 BOAT HULL CONSTRUCTION fAND PROPULSION William S. Brian and'Ferdinand J. Birk, Owensboro, Ky.

Application April 12, 1943, Serial No. 482,792 8 Claims. I (Cl. 115-11) This invention relates to boat hull construction and propulsion particularly designed to obtain high speed with maximum conservation of power.

One of the objects of this invention is to provide a boat or ship of that type, the under side of which is formed as a longitudinal tunnel by the provision of lateral downwardly extending longitudinal fins, with which propulsion is secured by means of a blower on the ship which discharges air beneath the hull under suflicient pressure to lift the hull and support it upon a layer of compressed air confined between the fins, and of sufiicient velocity to propel the boat forwardly by reaction of the escaping air fiow against the water wake.

In a boat of this type, as previously known, an example of which is disclosed in the patent to Dunajelf, No. 1,412,848, granted April 18, 1922, the bow portion of the boat is designed to travel normally supported by the water, creating a resistance to forward movement which practically nullifies the forward propulsive force.

-One,- of the objects of the invention therefore is tOl provide the hull with a downwardly and rearwardly extending injector or Venturi at the front,'formed' by a swinging vane anterior to the bow proper and forming with it a Venturi orifice which changes itspitch with the volume of air supplied by the blower, increase in the volume of air causing said Venturi vane to be pulled away from the water and toward the bow proper, caus ing airto be sucked into the tunnel or tunnels at the front of the boat by the partial vacuum created insaid Venturi, so that the water displacement of the boat is reduced solely to the volume of the submerged-portions of. the fins, whereby forward propulsion is provided not only by the impact of the escaping air on the wake, but also through the partial vacuum created in front of the Venturi vane as Well as by the partial vacuum produced in front of the blower which furnishes the motive power.

Afurther object of the invention is to provide a boat hull of such design that it will, when supplied with air at sufiicient pressure, ride with enough clearance between thehull and the water, yet sealed by the Venturi in front and by lateral fins, so that when traveling at high speed in rough sea it will allow the waves to come in contact with the Venturi vane only, causing said vane to swingto'ward the hull, permitting the boat proper to ride over the waves without coming into direct contact with any great part of them; T r r Other objects of the'invention will appear as as the following description of a preferred embodiment thereof proceeds.

In the drawings which accompany and form a part of the following specification, and through out the several figures of which the same characters of reference have been employed to designate identical parts:

Figure 1 is a side elevation of a boat or ship, embodying the principles of the invention, the hull being shown in rest position;

Figure 2 is a similar view showing the position of the vessel and of the bow and. stem vanes when in forward motion;

Figure 3 is a front view in elevation;

Figure 4 is a cross-sectional view illustrating the stabilizing function of the middle fin;

Figure 5 is a front end view, partly in section, showing a slightly modified form of the invention;

Figure 6 is a fragmentary side view in vertical section, of the modification shown in Figure 5;

Figure 7 is a view similar to Figure 5, showing the hull in listed position;

Figure 8 is a longitudinal vertical section of another modification of the invention;

Figure 9 is a front view in elevation, of still another form of the invention.

Referring now in detail to the invention as illustrated in Figures 1 to 4, inclusive, the numeral l represents as a whole the hull proper, having the bow 2, stern 3, bottom 4 and deck 5. The sides of the hull proper are produced forwardly, rearwardly and in a depth direction with respect to the hull proper, forming the longitudinal side fins 6 and 1 which are sufliciently deep so that their lower portions are submerged in all positions of elevation of the boat. A central fin 8 may be provided parallel to'the side fins for effecting stabilization of the hull, although the central fin is not essential to the broad inventive concept. 7

A hood structure 9 is provided anteriorto the bow 2, the forward portion of which, as shown, is supported by the bow as well as by the forwardly extending portions of the fins 6 and 7. The central portion of the hood 9 is constructed to form a blower housing I 0, the front of which is preferably, but not necessarily, in a transverse-plane perpendicular to water level andltheposterior portion of which inclines downwardly. toward the rear, communicating with the longitudinal'tum nels 2| and 22 formed beneath thebottom 4 and betdwgen the downwardly extending fins 6, 1 an A power plant H is mounted in the boat having a shaft I2 which extends into the housing It and operates a blower rotor 13, preferably of the wind tunnel type, mounted in the housing iii. A swinging bow vane i4, made in two parts Ida and lab to pass the middle fin 8, is pivotally mounted at the lower forward end of the hood structure 9, and is of such depth that the lower end I5 is submerged when the boat is at rest, even when it is lifted on a cushion of air just prior to assuming forward motion. The bow vane is normally inclined downwardly toward the rear but divergently to the bow 2, as shown in Figure 1, being limited in its amplitude of outward swing by the stops l6 formed on the fins 6, 1 and 8. The bow vane 14 is limited as to its inward swing by. the stops [1, also formed as part of or secured to said fins. The depth of the bow vane is such submerged portions of the fins 6 and 1, so that the total displacement which has to be resisted is limited to the volume of the submerged portions of the fins 6 and 1. Resistance to forward propulsion is thus reduced to a minimum.

The propulsive force is not only the reaction of the rearwardly moving column of air against the water wake, but it is also augmented by the vacuum produced in front of the bow vane I4 and by the vacuum created in front of the blower where the latter faces in a forward direction, as

shown. With the propulsive power thus increased, and the displacement resistance diminished to a minimum, a vessel constructed according to the principles of the subject invention should be capable of making great speed with comparatively small expenditure of power.

that when it rests against the-stop H, the. lower end I5 is above water level in the lifted position of the hull.

A stern vane i8 is pivotallymounted; at the stern of the hull between the fins 6 and I, being of sufficient depth to have-its lower end I9 submerged when the boatis in its lifted position prior to its assuming forwardmotion. Said stern vane, as shown, is biased towards vertical position by a spring of such strength as to resist the opening movement ofsaid stern vane until the air pressure beneath the hull is greater than that merely sufficient to lift the hull, beyond which pressure the stern vane. swings upwardly, permitting the, escape of air. Other means, the equivalent of. the. spring 29. may be.

employed to control the. stern vane.

The operationof the boat is asiollows. Nor- -mally, whenthe blower i3; is. not running, the.

vesselwill rest at the normal water level represented by the line ab, the hull proper displacing sufficient water to support the hull. VThen the blower is, started, a, large, volume. of air under iderab e pre ure. and. velocity. is forced be-. neaththe boat within theconfines established by the fins 6 and l and the bow. and stern vanesv M and [8, respectively. This lifts. thehull above the water level'to a position, with, respect to said water level ind-icatedby the linedcd. In thisposition the bow vane I4, aswell as the stern vane it, still dip beneath the, surface .of the water. while the side 6 and I l: arestill submerged, so that no air escapes, and there is, no .forwardmovement. Asthe pressure andivelocity of air deliveredby theblQ-Wer increases, the resistance of th spring 28; will-be overcome so that the stern vaneflt-swings upwardl toward-the rear until h lower d e l9.aemerges.from. the water, providing an exitat the stern for. theescape of air. This rearwardly escaping air jetis. confined between the rearwardly extending portions, of the side fins hand I so as. to secure maximum reactive propulsive pressure against the water wake rearwardly of the stern. As soon as a current. of air has thusbeen established, the. increasedvelocity of thejet from theblower has a practical Venturieffectin drawingthe bow vane win wardly against the stop ll, lifting the lower edge of said vane above the water level. The injector action of the air. jet. passing-between the bow 2 and the bowvane I l entrains a jet of air from, the body of air in front of the ship, drawing this air through the space beneath the raised lower edge of the bow. vane. l4.

With the bowand stern vanes thus raised, an (pen ended air tunnel. is termed beneath the hull and between the fins 6 and 'L'the boat being en tirely lifted from thewater excepting a to. th

The purpose of. the central fin 8 is to quickly stabilize. the boat to dampen rolling of the hull. It is obvious from Figure 4 that if air is passing through the longitudinal tunnels; 2'1, and, 22 defined-between the fins 6., I: and 8, and'the boat rolls to the position shown, the increased air pressure in the tunnel 2 I; and. decreased pressure in the tunnel 22 willquickly restore the vessel to aneven keel.

While the Venturi actuation of: the front'vane i4 is desirable as; giving anadded impetus to the forward movement of the hull. throughthe entrainment, of; forward air. with the resultant vacuum in frontof the bow vane, this. action is.not

essential, it being merelynecessary. thatzthe bowvane be-hinged and that-zit. be of;such lengthas to remain submerged longer than thesternvane. Then when the stern vane lifts, establishing an air jet against the water. wake so that thehull begins to, move. forward, the bow vaneswings back until its bottomedge just trails the water,

preserving; an air seal between said vane and the water, the forward resistance between-the boat and the water-being thusreduced to aminimum.

In that fornrof the invention shown in Figures: 5 and: 6,. the chamber Within the. blower housing 10; is provided :with a vane 23, iournaled' about that. partof, the shaft lZKWhiCh extends within the housing, l-flpgand which is normally in.

the vertical plane of said middle fin when 7 the hullis on an even .keel. and-is; balancedbythe weightsZfi or otherequivalent. means so that it remains in a vertical plane, regardless of the list of the hull, The. middle fin 8 extends Within the housing lasubstantially up. to'.the lower edge of the vane 23-; Thus, when the-hull is in listed position, aspillustrated. in Figure. 8; the vane 23 diverts the; major prop0rtion ofthe output of the blower i3 .intothedepressedtunnel; further increasing the air compression in said tunnel and themore; quickly stabilizing the hull;

u 3 hO S. a ;m.odifi.edwform' of ithe .invention similar to-that disclosed in Figures: rm 4, excepting that the depth of draftcreated by the: downwardly extending fins .6, l and 8 isrelieved by having the lowerportions ofsaid fins constructed in theform; of :a-seriesof "lapping dagger-boards ll-pivoted to; the. fins. at their for ward ends, and; Which-lift. upon making contact with the bottom, permitting. the vessel to navigate shallow waters.

Figure 9 depicts a modified 'form of the in vention whieh is, in generaLsimilar in construction and modeofoperation to; that shown inthe i group of Figures 1 to 4, inclusive,- but: which direfers from the latter inthat independent blowers 28,. and 29; in individualhousings 3.0 ..and ihoods 3|, independently serve the respective tunnels 2 land 22. The provision of the two blowers adds flexibility to the operation and control: of the vessel, in that the speeds of the blowers may be independently varied to effect stabilization'of thehull when rolling and that through independent control of the blower speeds differential action of the Venturi vanes Ma and l4b'may. be produced as well as different pressures at opposite sides of the water wake at the stern whereby steering of the vessel through difierential blower pressures may be accomplished.

It is, .of course, to be understood that the illustrated embodiment of the invention is largely diagrammatic and serves solely to illustrate the broad inventive concept. The detals of construction and the arrangement of parts, as shown, are therefore not to be construed as limiting the invention which is defined in th appended claims.

What we claim as our invention is:

1. In a power boat, the combination of a hull having longitudinal side fins extending depthwise below the hull bottom forming a longitudinal tunnel, a blower on said boat for delivering air to the forward part of said tunnel in a rearward direction, a stern vane at the rear of said tunnel having means imparting a biasing force thereto in a direction to close said tunnel, a hinged bow vane normally closing the front end of said tunnel wherebi said boat is lifted on a layer of air under pressure accumulated in said tunnel, said stern vane being opened by air pressure in said tunnel in excess of said biasing force to discharge the air flow from said tunnel against the water wake, and an injector at the forward end of said tunnel through which said blower delivers airto said tunnel, effective when the boat moves forward responsive to the reactive force of air against the water wake, to lift said bow vane above the water, entraining air from beneath said bow vane, thereby creating a forward vacuum which adds impetus to the forward movement of the boat.

2. Power boat as claimed in claim 1, the induction end of said blower facing forwardly whereby the vacuum created in front of said blower is an added component of the forward propulsive force.

3. Power boat as claimed in claim 1, including a central longitudinal fin extending depthwise beneath the hull bottom defining with the side fins a pair of longitudinal tunnels commonly served by said blower whereby stabilization is secured u-pon rolling of the hull, through the simultaneous compression of air in one tunnel and its expansion in the other tunnel due to differential water displacement on opposite sides of the hull.

4. In a power boat, the combination of a hull having longitudinal parallel side and center fins extending depthwise below the hull bottom forming parallel longitudinal tunnels beneath the hull bottom, a blower casing communicating with the forward portions of said tunnels, a blower in said casing delivering air rearwardly through said tunnels, hinged stern and bow vanes normally closing the ends of said tunnels whereby said boat is lifted upon a layer of air under pressure accumulated in said tunnels, means imparting a closing force to said stern vane, the latter being opened by air pressure in said tunnels in excess of said closing force to discharge the air flow from said tunnel against the water wake, and a gravity stabilized vane hingedly mounted in said casing separating the latter into two chambers, said vane being in the plane of said. oenterfin when the boat is on an even keel, but swinging relative to' said boat when thelatter rolls whereby a larger proportion of the air output from said blower is delivered to the more depressed of said tunnels for augmenting. the stabilizing effect of the differential air pressure in the respective tunnel incident to the listed position of the boat.

5. In a power boat, the combination of a hull having longitudinal parallel side and center fins extending depthwise below the hull bottom forming parallel longitudinal tunnels beneath the hull bottom, a blower casing communicating with the forward portions of said tunnels, a blower in said casing delivering air rearwardly through said tunnels, hinged stern and bow vanes normally closing the ends of said tunnels whereby said boat is lifted upon a layer of air under pressure accumulated in said tunnels, means imparting a closing force to said stern vane, the latter being opened by air pressure in said tunnels in excess of said closing force to discharge the air flow from said tunnel against the water wake, a gravity stabilized vane hingedly mounted in said casing separating the latter into two chambers, said vane being in the plane of said center fin when the boat is on an even keel, but swinging relative to said boat when the latter rolls whereby a larger proportion of the air output from said blower is delivered to the more depressed of said tunnels for augmenting the stabilizing effect of the differential air pressure in the respective tunnels incident to the listed position of the boat, and an injector at the forward end of said tunnels through which said blower delivers air to said tunnels, effective when the boat moves forwardres-ponsive to the reactive force of air discharging from said tunnels against said water wake, to lift said bow vane above the water, entraining air from beneath said bow vane, thereby creating a forward vacuum which adds impetus to the forward movement of the boat.

6. Power boat as claimed in claim 1, the lower portions of said fins each comprising a series of tilting plates arranged longitudinally, pivoted at their forward ends to the fixed portions of said fins.

7. In a power boat, the combination of a hull having longitudinal side and center fins extending depthwise below the hull bottom forming longitudinal tunnels beneath the hull bottom, a

I blower on said boat for delivering air to the forward portions of both tunnels in a rearward direction, a stern vane at the rear of said tunnels having means imparting a biasing force thereto in a direction to close said tunnels, hinged bow vane normally closing the front ends of said tunnels, whereby said boat is lifted on a layer of air under pressure accumulated in said tunnels, said stern vane being opened by air pressure in said tunnels in excess of said biasing force to discharge the air flow from said tunnels against the water wake, and an injector at the forward ends of said tunnels through which said blower delivers air to said tunnels, effective when the boat moves forward responsive to the reactive force of air discharging from said tunnels against the water wake, to lift said bow vanes above the water, entraining air from beneath said bow, vanes, thereby creating a forward vacuum which adds impetus to the forward movement of the boat.

8. In a power boat, the combination of'a hull havinglongitudinal side and center fins extending depthwise below the hull bottom forming 1on-v gitudinal tunnels beneath the hull bottom, blower casings communicating with the respective tunnels at their forward ends, independently controlled blowers in said casings for delivering air to said respective tunnels in a rearward direction, a stern vane atthe rear of said tunnels having means imparting a biasingef orce thereto in a direction to close said tunnels, hinged bow vanes normally closing the front ends of said, tunnels whereby said boat is lifted on a layer of air under pressure accumulated in said tunnels,.saicl stern vane being opened by air pressure in said tunnels in excess of said biasing force to discharge air flow from said tunnels against the'water wake, and injectors at the forward endsof said tunnels through which said blowers deliver air to the respective tunnels, efiective when the boat moves forward responsive to the reactive force of air against the water wake to lift said bow vanes above the water, entraining air from beneath said bow vanes thereby creating a forward vacuum which adds impetus to the forward movement of the boat.

1 WILLIAM S. BRIAN.

FERDINAND J. BIRK. 

